Remarketing is a feature that helps you reach the users that visited your site.
For example you can show custom ads to user that visited a section of your site. Or you can use it to target users that visited your e-shop but didn't place any sale.

Remarketing is a feature that helps you reach the users that visited your site.
For example you can show custom ads to user that visited a section of your site. Or you can use it to target users that visited your e-shop but didn't place any sale.

Agreed with what you said, however would like to add few cents, that this is one of the effective and cheaper form of advertising.

Additionally, Re-marketing helps you in analyzing the traffic and you get to know many answers regarding audience behavior on your website.

As regards with Re-marketing on Adwords, you can put several conditions now, like, you want to target only those people who have stayed for 60 seconds or longer on your site.